1. Field of the Invention
The present invention relates generally to security devices, and more particularly to devices for protecting vehicles against sabotage.
2. Prior Art
Terrorist activities abound throughout the world, and the situation worsens with each passing year as the number and viciousness of crimes perpetrated against persons and property increasingly mounts.
One frequently employed terrorist act involves the planting of incendiary or other explosive devices in motor vehicles. Frequently such devices are placed in the vehicles engine compartment and wired to the ignition system, triggered for explosion when the vehicle's driver activates the ignition. However, various means have been provided to prevent the placement of such devices or at least to make placement substantially more difficult then was heretofore the case. For example, armored cables discourage access to the vehicles wiring; anti-theft devices trigger an audible alarm when the hood latch, trunk latch, or a door is tampered with; locking mechanisms or other restraints on vehicle hoods deter access to the engine compartment; and heavy gauge sheet metal enclosures at the underside of the engine compartment, and in some instances, the entire underside of the vehicle, discourage penetration from that sector.
By and large, the entire vehicle has been made more impenetrable in cases where the user, driver and/or passenger(s) is an individual whose position makes him or her an attractive target or attack. For example, individuals in diplomatic or foreign service, even at relatively low levels of the chain of command, are all to often subject to vandalism or harassment, if not more life-threatning terrorism. Accordingly, such individuals are now being afforded more secure vehicles or vehicles provided with devices to offer greater security to their safety. Even such areas as windshields and window glass have been improved such as by making them of transparent plastic such as Lexan or of other forms of bullet proof "glass" to prevent them from being breached.
One area of the motor vehicle that remains virtually unprotected is the exhaust system. Terrorist and other criminals have been known to thrust explosive devices into the tailpipes of vehicles, where the device is hidden from view and is triggered when the exhaust pipe reaches an elevated temperature after a few minutes of driving. In other reported instances, non-explosive objects have been forced into the tailpipe with the intent that the barrier they present to exhaust gases resulting from combustion will cause engine failure within a short period of driving, to render the occupants of the vehicle easy targets of attach in an unsecured, location; or worse, to cause the occupants of the vehicle to be overcome as the toxic fumes enter the passenger compartment.
The terrorist typically carries out a criminal act only if it can be accomplished with unimpeded dispatch. The action must be swift and sure--otherwise, the liklihood of detection of the terrorist activity or the destructive means employed weighs against going forward. On the other hand, the cost of security can rise to the level that it becomes prohibitive to afford complete protection from attack.
It is therefore a principal object of the present invention to provide a simple, relatively low cost, yet effective deterrent against a common form of sabotage of motor vehicles.
A more specific object of the present invention is to provide a simple and effective means for preventing vehicular access via the exhaust system.